I don't have the original poster's pack, but I have a pack that replicates the issue.
[media]The resource pack I attached contains a stereo version of the 'Stal' record. When played in a jukebox, the volume of the sound is left unaffected by distance. This seems to be a bug with all sounds that are stereo, not just jukebox sounds.
This bug has returned in pre-5.
I can second this. the bug seems to be back in it's entirety, and not only in /playsound.
Yes.
Confirmed for 1.14.1-pre2.